08 August 2011

A 72-year old woman presents with a complaint of headache and that her right eye "just isn't working right." She is generally healthy, with only an idiopathic anemia, and no associated symptoms other than some fatigue and poor appetite. She characterizes the headache as being a sinus headache, and notes that it has been occurring on and off for a month or so, though she has never had any fever or nasal congestion/drainage. She has had "eye problems" related to this headache in the past, but today it is more severe than before.

When the patient looks at you, this is what you see:

She cannot voluntarily retract the right eyelid. It is nontender, and when you retract it for her, she complains of diplopia. You see this:

The right pupil is dilated and fixed; the left is 3 mm and reactive. Note that with level gaze the eyes do not seem quite conjugate. The right eye is deviated mildly down and out. When you ask the patient to look to her left:

There is no movement of the right eye at all. And when you ask her to look up:

Again the right eye does not move. Same with downwards gaze. On attempted right gaze you see this:

But on right gaze the patient still complains of diplopia. Vision in the right eye is grossly intact to confrontation. The right pupil reacts neither to light or attempted accommodation (on a very limited exam). Neurological exam is otherwise entirely normal, including as many cranial nerves as an ER doctor remembers how to test.

So -- what is the clinical finding here, and where is the lesion most likely to be based on the information you have?

8 comments:

It's pretty obvious that the defects are due CN-III disfunction. The triad ptosis, pupil dysfunction and diplopia distinguishes this from CN-VI impairment. It is also obvious from the clinical observation that the impairment is somewhat before the nerve branches to the inferior and superior rami. Impacts to a single branch would cause either diplopia and pupil dysfunction or pupil ptosis but not both.

Given the patient's age, complaints of headaches and otherwise unremarkable medical history, my first guess is a subarachnoid bleed or berry aneurysm. Other diagnoses to be considered include infectious demyelinating or vascular compromise syndromes or malignancy.

Further investigation would include MRI and MRA and a referral to neurology.

I'm so pleased to see one of these that covers my limited knowledge of neuroanatomy.

^^^ This is what happens when you have unskilled help typing your entry while you dictate from the car. I know full well that pupils don't suffer from ptosis (hell, they probably appreciate the dark).

My mom presented to the ED, while coincidentally on a business trip to the city of her oncologists, with acute onset ptosis, but intact accomodation, acuity, pupilary response and conjugate gaze. The neuro resident was convinced it was Horner's Syndrome. Zebras.

The initial, totally reasonable suspicion from both the ED attending and neurology fellow was a brain met of her breast cancer, but given the extensive nature of her disease and the fact that she'd been clean on MRI and PET for years despite extensive skeletal and hepatic disease caused a good deal of healthy skepticism on the part of the oncologist and neuro attendings.

Good thing. It turned out her brain was still clean, but a nasty little bone met on the pars orbitalis was mechanically irritating the levator palpebrae superioris, causing inflammation and swelling.

Radiotherapy directed at the offending lesion produced partial response in four days and complete response over ten or so, with no significant long-term deficits.

The patient here will probably not fare so well, I'm guessing, given that she has had symptoms for a longer period of time. Wouldn't the rule here be that either compression or vascular infarction eventually damages the nerve beyond the possibility of rapid return to function?

Ugh, neuroanatomy!I'm guessing right third cranial nerve palsy. Several possible etiologies.I'll take a wild guess and say posterior communicating artery aneurysm, but only because the Wills Eye Manual says this is the "more common" etiology for isolated third nerve palsies involving the pupil.What does the MRI/MRA of her noggin show?

R pcomm aneurysm until proven otherwise. This gal doesn't leave the ED without a MRI/MRA brain and emergent neuology/neurosurgery consult or transfer to somewhere where that can be accomplished. Try not to panic, but she is a massive subarachnoid hemmorhage just waiting to happen.

Shadowfax

About me: I am an ER physician and administrator living in the Pacific Northwest. I live with my wife and four kids. Various other interests include Shorin-ryu karate, general aviation, Irish music, Apple computers, and progressive politics. My kids do their best to ensure that I have little time to pursue these hobbies.

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